updated 07:55 am EST, Wed March 4, 2009

Amazon Kindle for iPhone

Amazon on Wednesday surprised the e-book field by launching Kindle for iPhone (App Store link). The free software, which also supports the iPod touch, is the first outside of the Kindle reader itself to support the proprietary Kindle e-book format and takes advantage of Amazon's inter-device sync to both buy and continue books on the iPhone. Purchases made from a Kindle, Kindle 2 or the web (including through Apple's mobile Safari browser) are downloadable and can be left at one page on a given device to be resumed later on another, even with different page formatting.

Readers get some of the Kindle-specific reading features on the iPhone, including adding bookmarks, changing font sizes and viewing existing highlights and notes made by a Kindle device.

Amazon had previously pledged that it would expand Kindle reading to include other devices such as cellphones but hadn't outlined its strategy today. The company sees the iPhone app as a way to "catch up" on Kindle books but is often seen as directly competing with the iPhone, which itself has been increasingly gaining momentum through both free and paid books either through book aggregator apps, such as Stanza, or else title-specific apps like Knife Music.

No horizontal view? Guess that kind of makes sense because it preserves the aspect ratio of the Kindle but portrait on the iPhone simply isn't wide enough.

Overall though, this seems like a great strategy on Amazon's part: get people hooked on the Kindle store which definitely has an order of magnitude more content than any other ebook store->people start to get curious about physical Kindle.

So this makes the iPod touch/iPhone plateform more attractive (good for Apple) and let's people try out eBooks from the Amazon store without forking out close to $400 (good for Amazon). Sony is the party that loses. Their propietary bookstore is now a little less attractive relative to Amazon's.